Electric control device



H. A. RIDER. JR

Dec. 5, 1967 ELECTRIC CONTRGL DEVICE Filed March lo,

INVENTOR Henry A. Ridendn BY WC/4W 4L. m

ATTORNEY United States Patent O 3,356,975 ELECTRIC CONTROL DEVICE Henry A. Rider, Jr., Westminster, Calif., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Mar. 15, 1966, Ser. No. 534,456 8 Claims. (Cl. 335-160) This invention relates generally to electric control devices and more particularly to electric control devices of the type comprising a movable magnetic structure having relatively movable parts.

In certain types of electric control devices it is desirable to provide a magnetic actuator constructed such that the opposite legs of one of the magnetic structures are movable relative to each other. This type of construction is desirable, for example, in a type of direct current electromagnetic contactor wherein the opposite legs of one magnetic member move into a particular mating relationship with another magnetic member. The relative movement enables separate alignment of the opposite legs with the other magnetic member.

An object of this invention is to provide an electric control device comprising an improved unitary magnetic structure comprising relatively movable parts.

Another object of this invention is to provide an electric control device comprising a unitary magnetic struc ture comprising relatively movable parts, which control device comprises improved mounting means for securing the relatively movable parts of the magnetic structure together and for securing the magnetic structure to a contact carrier.

Another object of this invention is to provide an irnproved contactor.

The invention, both as to construction and operation, together with additional objects and advantages thereof, will be best understood from the following detailed description when read in conjunction with the accompanying drawings.

In said drawings:

FIGURE 1 is a sectional View taken generally along the line I-I of FIG. 2;

FIG. 2 is a sectional view taken generally along the line II-II of FIG. l; and

FIG. 3 is a perspective view of certain separated parts of the contactor illustrated in FIGS. 1 and 2.

Referring to the drawings, there is shown in FIGS. 1 and 2 an electric control device 5 that can be more speciiically termed an electromagnetic contactor. The contactor 5 comprises a rigid base plate 7 of magnetic material and an insulating housing 9. The insulating housing 9 comprises an insulating base part 11, an insulating upper part 13 and an insulating cover part 15. The insulating base part 11 of the housing 9 is secured to the magnetic base plate 7 by means of two screws `17 (only one of which is seen in FIG. 2). Each of the screws 17 also lCC able openings in the magnetic base plate 7 and pressed into position to provide an interference type rigid mounting of the magnetic leg members 29 on the base plate 7. The magnetic leg members 29 and the base plate 7 cooperate to form a stationary magnetic structure. A double coil structure 33, comprising two conducting coils and 37 embedded in a plastic case 39, is mounted within the housing 9 on the base plate 7. As can be seen in FIG. 1, each of the coils 35 and 37 is disposed over a dilferent one of the stationary magnetic leg members 29. Suitable terminals (not shown) are provided for permitting electrical connection of the terminals 35, 37 in an electric circuit.

A movable structure 41, comprising a movable magnetic structure 43 and a contact assembly structure 45, is suitably supported within the housing 9. The contact assembly structure 45 comprises a molded insulating contact carrier 47 that is formed with four window openings 49 therein. A separate movable bridging contact structure 51 is supported in each of the windows 49 of the Contact carrier 47. Each of the movable bridging contact structures 51 comprises an elongated conducting member 53 having a pair of movable contacts 55 supported at the opposite ends thereof. A separate spring member 59 is positioned in each of the windows 49 to mount the associated bridging contact structure 51 in position on the Contact carrier 47 and to provide resilient contact pressure in the closed position of the contacts. As can be seen in FIG. 1, the contactor 5 is a four pole contactor with four bridging Contact structures 51 simultaneously operated by the common contact carrier 47. A pair of spaced stationary contacts is supported in each pole to cooperate secures a Z-shaped support member 19v to the base part 11 of the housing. The upper part 13 of the housing 9 is secured to the lower part 11 by means of two screws 21 (only one of which is seen in FIG. 2). Each of the screws 21 threadedly engages the upper leg of the associated Z-shaped support 19` to secure the upper part 13 of the housing 9 in place. The cover part 15 of the housing 9 is secured to the upper part 13 by means of two screws 23 (only one of which is seen in FIG. 2) which screws 23 are threaded into tapped metallic inserts 25 that are mounted in the upper housing part 13.

Two generally cylindrical shaped magnetic leg members 29 are Xedly secured to the magnetic base plate 7 in an upstanding spaced relationship. Each of the magnetic leg members 29 is provided with a bottom part 31 of reduced diameter. The bottom parts 31 are forced into suitwith the associated bridging contact structure 51. Each of the stationary contacts 61 is mounted on a separate conducting terminal strip 63. The terminal strips 63 extend out through suitable openings in the housing 9 to provide externally accessible parts for receiving suitable screw members that may be used to electrically connect the terminals in an electric circiut. As can be seen in FIGS. 1 and 2, the cover member 15 is provided with four internal cavities 67 (FIG. 2) for enclosing the contacts of the four pole units of the contactor.

The movable magnetic structure 43 is a generally U- shaped unitary structure comprising a pair of spaced magnetic legs 71 and a magnetic connecting part 73. As is best seen in FIG. 3, the connecting part 73 is a oneepiece member generally U-shaped in cross section comprising a pair of legs 75 and a bight portion 77. The legs 75 of the U-shaped connecting part 73 extend out past the bight portion 77 to provide spaced shoulder parts at both ends of the connecting part 73. Each of the legs 71 of the movable magnetic structure 43 comprises a main body part 79 that is a solid member of magnetic material formed in the shape of a cylinder. Each of the magnetic leg members 71 comprises a solid cylindrical neck part 81 having a reduced diameter that tits between the legs 75 of the connecting part 73 with enough clearance to permit limited universal movement of the member 71 on the connecting part 73. Each of the magnetic members 71 comprises a solid cylindrical head part 83 having a diameter greater than the dimension between the shoulder parts of the connecting part 73. The head parts 83 of the leg members 71 rest on the upper surfaces of the opposite shoulder parts to support the members 71 on the connecting member 73. The connecting member 73 is provided With a separate opening 85 in each of the opposite legs thereof.

As can be seen in FIGS. 1-3, the molded insulating contact carrier 47 is provided with a cavity 87 at the lower side thereof formed by opposite end walls 89and opposite side walls 91. The end walls 89 and side walls 91 are molded integral with the insulating contact carrier 47.

When it is desired to secure the movable magnetic structure 43 to the insulating contact carrier 47 and to secure the parts 71, 73 of the movable magnetic structure 43 together, the separate magnetic leg members 71 are moved into the position seen in FIG. 3 with the neck parts 31 thereof being moved between the opposite shoulder parts of the member 73 from the opposite ends of the member 73 to position the members 71 such that the head parts 83 thereof rest on top of the shoulder parts. The bight portion 77 limits inward movement of the leg members 71 on the connecting member 73. Thereafter, the magnetic structure 43 is moved up into the cavity 87 of the insulating contact carrier 47 and a flat mounting plate member 93 is then passed through spaced openings 95 in the insulating contact carrier 47 and also through the openings 85 in the spaced legs of the connecting part 73 of the movable magnetic structure 43. The external opposite ends of the mounting plate member 93 engage on ledges 97, formed as molded integral parts of the insulating contact carrier 47, to thereby connect the movable magnetic structure 43, the insulating contact carrier 47. As can be seen in FIG. l, the opposite end walls 89 limit outward movement of the magnetic legs 71 so that the operation of mounting the connecting member 73 of the movable magnetic structure 43 to the insulating contact carrier 47 serves to capture the opposite legs 71 of the movable magnetic structure 43 in place to thereby secure the parts 71, 73 of the movable magnetic structure 43 together. As can be seen in FIGS. 1 and 2, a resilient pad 99 is placed between the upper cavity surface of the insulating contact carrier 47 and the upper surfaces of the magnetic members 71, 73 to provide a resilient backing to absorb shock during operation of the contactor 5. The pad 99, which is under compression in the mounted position, biases the member 93 against the contact carrier 47 to prevent easy displacement of the member 93.

The movable magnetic structure 43 and insulating contact carrier 47 are moved into the mounted position in the housing 9 before the upper part 13 and cover 15 of the housing 9 are mounted in place. There is a separate compression spring 101 (FIG. 2) on each of the two Z- shaped supports 19, which springs 101 engage the contact carrier 47 to bias the contact carrier 47 and movable magnetic structure 43 upward to the unattracted position seen in FIGS. 1 and 2. In the unattracted position of FIGS. 1 and 2, the contacts 55, 61 are in the open position.

Each of the spaced legs 71 of the movable magnetic structure 43 comprises a lower integral part 103 that is shaped in the form of an inverted truncated cone. Each of the magnetic members 71 is provided with a tapped opening at the lower end thereof. A separate non-magnetic guide member 105, having a threaded part 107, is screwed into the tapped opening of each of the members 71. A non-magnetic washer member 109 is secured to each magnetic leg 71 to engage a flat ring shaped mating surface 110 on the associated stationary magnetic leg 29 in the closed position of the electromagnet to provide a nonmagnetic gap between each movable magnetic leg 71 and associated stationary magnetic leg 29 to thereby provide for quick release of the movable magnetic legs 71 from the stationary magnetic legs 29 when the coils 35, 37 are deenergized. As can be seen in FIG. l, each of the members 105 is provided with a slot 111 therein for receiving a screwdriver. As can be seen in FIGS. 1 and 2, each of the members 105 is provided with an opening in the threaded part 107 thereof, and a nylon plug 113 is inserted through the opening extending out of the opening at both ends thereof. As the members 105 are screwed into position the protruding ends of the nylon plugs 13 are sheared off between the threads to provide a tight fit to maintain the non-magnetic guide pins 105 in position during operation of the contactor. Each of the magnetic legs 29 of the stationary magnetic structure 7, 29 is provided with an opening 117 therein for receiving the associated non-magnetic guide pin 105 with enough clearance to permit axial movement of the member and tov guide the member 105 for axial generally rectilinear vertical movement. Each of the magnetic parts 29 of the stationary magnetic structure 7, 29 comprises a depressed part 121 that is shaped to mate in a closely spaced relationship with the frusto-conical part 103 of the associated magnetic member 71 in the closed position of the movable magnetic structure 43.

When the coils 35, 37 are energized, the current through these coils generates magnetic flux which travels in a magnetic circuit from one of the stationary magnetic legs 29 through the base plate 7, the other stationary magnetic leg 29, the air gap between said other stationary magnetic leg 29 and the adjacent movable magnetic leg 71, the magnetic connecting member 73, the other movable magnetic leg 71, the air gap between the other magnetic leg 71 and said one stationary magnetic leg 29 to said one stationary magnetic leg 29.

The contactor 5 is shown in FIGS. 1 and 2 in the deenergized position with the four bridging contact structures 51 in the upper open position. The parts are maintained in the position seen in FIGS. 1 and 2 by the compression springs 101 which bias the movable structure 41 upward to the position seen in FIGS. 1 and 2. The contactor 5 is constructed with solid magnetic members of relatively large mass to provide efficient operation under the control of a direct current. When the coil 35, 37 is energized suciently to operate the contactor, the suiciency of which energization will be determined by the particular rating of the contactor, the movable magnetic structure 43 is attracted toward the stationary magnetic structure 7, 29, and the movable magnetic structure will move downward against the bias of the springs 101 to an attracted or closed position wherein the non-magnetic washers 109 of the movable magnetic legs 71 engage the mating surfaces 110 of the stationary legs 29. In this closed position of the electromagnet the truste-conical surfaces 103 of the movable magnetic legs 71 are in a closely spaced mating relationship with the associated surfaces 121 of the stationary magnetic legs 29. Thus in the closed position of the electromagnet there is a nonmagnetic gap between the movable magnetic legs and the stationary magnetic legs to permit quick release of the movable magnetic legs when the coils 3S, 37 are deenergized. The movement of the legs 71 is guided by the engagement of the non-magnetic guide pins 10S in the openings 117. The downward actuated movement of the movable magnetic structure 43 moves the contact carrier 47 downward to -a position wherein the movable contacts -55 of all four pole units engage the associated stationary contacts 61 thereby closing the four circuits controlled by the four pole units. As can be seen in FIG. l, the insulating contact carrier 47 is provided with two molded integral upper extensions 122 which extend out through two openings 123 in the cover 15 and which fit in the openings 123 in such a manner as to guide the contact carrier 47 for rectilinear movement. Upon deenergization of the coils 35, 37, the charged springs 101 return the contact carrier 47 upward to the unattracted open position seen in FIGS. l and 2 which movement moves the movable magnetic structure 43 upward to the open position seen in FIGS. 1 and 2. Although the pole units disclosed in FIGS. 1 `and 2 are norm-ally open pole units, it can be understood that the contacts could be arranged to provide normally closed pole units in a manner Well .known in the art.

. From the foregoing, it `can be understood that there is provided by this invention an improved electric control device comprising a unitary magnetic structure having relatively movable parts to enable alignment of the magnetic structure with the other magnetic structure of the electromagnet. The opposite magnetic leg parts 71 of the movable magnetic structure 43 are connected to the magnetic connecting member 73 in such a manner as to enable limited independent universal movement of the leg parts 71 on the member 73 to permit proper alignment of the guide pins 105 in the openings 117 and to enable positioning of the movable magnetic leg parts 71 in an aligned mating relationship with the stationary magnetic legs 29. During the assembly of the control device, the magnetic leg parts 71 are moved into the position seen in FIG. 3 on the connecting member 73, and the movable magnetic structure 43 is then moved up into the cavity 87 of the contact carrier 47 against a resilient pad 99 whereupon the support plate 93 is passed through the openings 95 in the contact carrier 47 .and the openings 85 in the connecting member 73 to connect the movable magnetic structure 43 to the contact carrier 47 `and to capture the parts 71, 73 together in the cavity 87. When the movable magnetic structure 43 is connected to the contact carrier 47 the end walls `89 of the cavity 87 pre vent removal of the legs 71 from the connecting member 73.

While the invention has been disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes in the structural details and arrangement of parts thereof may be made without departing from the spirit of the invention.

I claim as my invention: f

1. An electric control device comprising a stationary contact, a movable contact, an electromagnet comprising a stationary magnetic structure and a movable magnetic structure, means operatively connecting said movable contact with said movable magnetic structure, means operable to move said movable magnetic structure toward and away from said stationary magnetic structure to operate said contacts between opened and closed positions, one of said magnetic structures comprising a pair of spaced magnetic leg parts and a magnetic connecting part connecting said spaced magnetic leg parts, the magnetic circuit of said electromagnet extending through said spaced magnetic leg parts and said magnetic connecting part, and said spaced magnetic leg parts being movable relative to said magnetic connecting part and relative to each other to permit lalignment of said magnetic leg parts with said stationary magnetic structure during operation of said control device.

2. An elect-ric control device according to claim 1, and said one of said magnetic structures being said movable magnetic structure.

3. An electric control device according to claim 1, said stationary magnetic structure comprising a pair of spaced magnetic legs extending generally tow-ard said movable magnetic structure, said one of said magnetic structures being said movable magnetic structure, said movable magnetic structure comprising a generally U-shaped structure with said spaced magnetic leg parts extending from said magnetic connecting part in a direction generally toward said spaced magnetic legs of said stationary magnetic structure, and said spaced magnetic leg Iparts of said movable magnetic structure lbeing supported for limited universal-type movement on said magnetic connecting part.

4. An electric control device according to claim 3, said magnetic connecting part comprising a pair of spaced shoulder parts at each of the two opposite ends of said magnetic connecting part, each of said magnetic leg parts being supported on -a different pair of said pairs of shoulder parts, and each of said magnetic leg parts comprising `a part having a reduced dimension positioned between the associated pair of shoulder parts and a head part resting on the associated pair of shoulder parts to support the magnetic leg part on the magnetic connecting part.

5. An electric control device according to claim 4, each of said magnetic leg parts having a frusto-concal surface in proximity to the lower end thereof, said magnetic legs having surfaces formed to mate in a closely spaced relationship with said frusto-conical surfaces of said magnetic leg parts, each of said magnetic legs having an opening therein, and a guide pin supported at the lower end of each of said magnetic leg parts positioned in the opening of the yassociated magnetic leg to guide the associated magnetic leg part for generally rectilinear movement.

6. An electric control device according to claim 1, an insulating contact carrier, said movable contact being supported on said insulating contact carrier, said one magnetic structure being said movable magnetic structure, -said spaced magnetic leg parts being supported for limited movement on said magnetic connecting part, said insulating contact carrier said movable magnetic structure and said mounting means being constructed such that when said magnetic connecting part is mounted on said contact carrier said magnetic leg parts are captured in place on said magnetic connecting part.

7. An electric control device laccording to clai-m 1, said one magnetic structure being said movable m-agnetic structure, said movable magnetic structure comprising a generally U-shaped structure comprising a magnetic connecting part and a pair of spaced magnetic leg parts supported on said connecting part, said connecting part comprising a pair of spaced shoulder parts at each of the opposite ends thereof, each of said leg parts being supported on a different end of said connecting part, each pair of spaced shoulder parts being open at the associated end of said connecting part, each of said leg parts cornprising `a neck part having a reduced dimension and a head part above the neck part, each of the leg parts being moved into position into the open associated end of the connecting part with the neck part being positioned between the associated pair of spaced shoulder parts of said connecting part land with the head part resting on the associated 4pair of spaced shoulder parts of the connecting part to support the leg part on the connecting part, means limiting inward movement of said leg parts toward each other on said connecting part, said means which operatively connects said movable contact with said movable magnetic structure comprising an insulating contact carrier, said movable contact being supported on said insulating contact carrier, means mounting said connecting part on said insulating contact carrier, and said insulating contact carrier comprising Wall means adjacent the opposite ends of said connecting part to prevent movement of said magnetic leg parts 01T of said supported position when said connecting part is mounted on said insulating contact carrier.

8. An electric control device -according to claim 7, said connecting part comprising a center part generally U-shaped in cross section, said connecting part having opening means in the opposite leg parts thereof at said generally U-shaped part, said insulating contact carrier having a cavity lat one side thereof, said connecting part being disposed in said cavity, said insulating contact carrier having opening means therein and ledge means thereon adjacent said opening means, a mounting mem- -ber extending through said opening means in said insulating contact carrier and through said openings in said connecting part, and said mounting member resting on said ledge means on said insulating lcontact carrier to support. said connecting part on said insulating contact earner.

References Cited UNITED STATES PATENTS 2,528,777 11/1950 Persons 335--267 XR 2,897,316 7/ 1959 Brauneck 335-31 BERNARD A. GILHEANY, Primary Examiner.

GEORGE HARRIS, Assistant Examiner. 

1. AN ELECTRIC CONTROL DEVICE COMPRISING A STATIONARY CONTACT, A MOVABLE CONTACT, AN ELECTROMAGNET COMPRISING A STATIONARY MAGNETIC STRUCTURE AND A MOVABLE MAGNETIC STRUCTURE, MEANS OPERATIVELY CONNECTING SAID MOVABLE CONTACT WITH SAID MOVABLE MAGNETIC STRUCTURE, MEANS OPERABLE TO MOVE SAID MOVABLE MAGNETIC STRUCTURE TOWARD AND AWAY FROM SAID STATIONARY MAGNETIC STRUCTURE TO OPERATE SAID CONTACTS BETWEEN OPENED AND CLOSED POSITIONS, ONE OF SAID MAGNETIC STRUCTURES COMPRISING A PAIR OF SPACED MAGNETIC LEG PARTS AND A MAGNETIC CONNECTING PART CONNECTING SAID SPACED MAGNETIC LEG PARTS, THE MAGNETIC CIRCUIT OF SAID ELECTROMAGNET EXTENDING THROUGH SAID SPACED MAGNETIC LEG PARTS AND SAID MAGNETIC CONNECTING PART, AND SAID SPACED MAGNETIC LEG PARTS BEING MOVABLE 